Study on corrosion behavior of porous supports of ceramic membrane in HNO solution

In order to investigate the application performance of ceramic membrane in harsh environment, the change of the mass loss rate with corrosion time, the microstructure evolution, strength degradation and changes in pore structure and pure water flux (PWF) of macroporous supports (mass fraction 99% Al₂O₃) immersed in HNO₃ solutions (1-10 mol/L and 20-90°C) were investigated experimentally. The results showed that the corrosion of supports in HNO₃ solution occurred mainly at the neck between Al₂O₃ particles. The selective dissolution in neck played an important role in the mass loss of tubular supports and the leached elements were mostly Ca, Na and Al. It is clarified that the corrosion resistance of support is closely related with the components at the neck between Al₂O₃ particles. The three-point bending strength of corroded macroporous supports decreases as the mass loss of support increases. These results provide the base for improving of corrosion resistance of support and forecasting the life span of ceramic membrane in acidic environment.